Apple has finally updated their version of Libc, and it now includes getline(). \o/

The following patch fixes OpenWRT getline.h to not redefine it for 10.7. The one
caveat is, the includes (at least stdio.h) are needed before the #ifdef so thatDARWIN_C_LEVEL could be properly defined (it is not a compiler built-in define
like linux or APPLE).

This one fixes the host/include/getline.h. The next patch will mend the mkimage
package.